Drag-spindle mechanism



Nov. 6 1923. r

M. MAAG DRAG SPNDL MECHANISM Original Filed Dec. 3,1, 1918 WML Patend Nov.. 6, i923.

.MAX MMG, OF ZURICH, SWITZERLANB.

DRAG-SPINDLE MECHANISM.

Original application ied December l, 191, lSerial No. 269,081.

r October 27, 1920.

' To aZZw/iom t may cof/wem: V

Be it known 'that I, MAX MAAG, a citizen of the Re ublic of Switzerland, residing at Zurich, gardstrasse 219, Switzerland,

have invented new and useful improvements in Drag-Spindle Mechanisms, of which the. following is a specification.

This inventionrelates to driving mecha.-

-nism for a table or other rotatable element adapted to take up any lost motion between the members of the driving mechanism and the table and positively prevent any retro grade movement of the table while being driven in one direction.v

One of ythe objects df the invention is to provide a driving means 'for a rotatable machine tooi table oranalogous element which will. take up all-lost motion between the parts driving thetable and'wt the same time prevent any retrograde movement of said table or element, and which will further permit the table tobe driven in either direction. f'i

Another oheetof the invention. is to provide a irictional and also'a positive driving mechanism for a rotatable member, these mechanisms operating to rotate theelement at diii'erent speeds so thatl the frictional driving mechanism tends to crowd the ro- @0 tatable element against one side of the positive driving mechanism. v

Another object of the invention is to provide a positive and also a. frictional driving mechanism for a'rotatable element, both of' .35 theserlriving mechanisms rotating an element oil-'elements to which the table is rigid- 1y `attached so that during the rotation of t e element in either direction thefrictional mechanism will slip and. the table- `or ele- 40. ment be rotated positively in accordance with the rotative movement of the positive v [driving mechanism but will be forced, by

eans of the more rapidly operating frictional driving mechanism, against one side 65..' fthe positive driving mechanism.

O .ie feature that is particularly advantagoous is that the power mechanism may be reversed and the direction of rotation of f the element reversed Without danger of @59 -cramping the driving mechanisms against ,.eech other and ffixed position,

i -A nother ooject of the invention is to provide a clutch or other' means in the positive thus locking the element in Serial No. 419,999.

movement of the parts in the positive driving mechanism is` permitted to enable the .n

frlctional driving mechanism to first start 'Divided and. this application led to drivethe rotatable element in either direction.

. Another feature of the invention that enablesme to reverse the power means Without cramp-ing the AI nechanisms together is the ,clutch in the postive rotating means. This clutch is provided with teeth and grooves permitting, a limited rotary movement of' the power end Without moving the table driving` end of this positive rotary means. The amount of this idle movement betwn the members of this clutch is sufiicient to permit all the lost motion or backlash being taken up in the frictional driving means before the positive driving means becomes ef fective to drive 'the table in the opposite direction.

At each ,reversal oimovementof the power vmeans the positive rotating means remains ineiiective to rotate the element for an instant until all the lost motion in the frictional rotating members is taken up and the frictional means begins to lrotate, the element ,in theopposite direction.y As soon as the rictional mea-ns actually starts to drive the element in the opposite direction, the positive rotating means may become effective to ing and binding the mechanisms together. This applicationvfo-rms Va division of my copending application Serial No.` 269,081, filed December 31st, 1918.

With the above and other objects in View,

struction and ope-ration set-forth inthe 0lmy invention consists in the features of con- `rotate the element Without danger of cramplowing specification and illustrated inthe accompanying drawing forming a part hereof.

iin the accompanyingl drawing I have shown several modifications of the invention which are now deemed preferably, but it is to be understood that changes and modifica- 'tions may be made within the scope of the appended claims without departing from the spirit ofthe invention.

in the drawing: v Figure'l shows a plan view of one modi- Aiication of the invention with parts broken away to more clearly show the details of construction.

frame is shown at 10. and on this frame is mounted a rotatable table 11. 1t is the purpose of the present invention to provide driving means for positively rotating this table 11 in either direction in a manner which will prevent any lost motion between it and its driving means.

The driving means for the table 11 comprises a shaft 12 on which is mounted a bevel gear 13. In mesh with the bevel gear 13 is a bevel gear 14 mounted on a short shaft 14ea and fixed thereto in any convenient manner. In mesh with the bevel gear 14 is a bevel gear 15 mounted loosely on the shaft 16. Shaft 16 is provided with a conical portion 17 fitting a corresponding conical portion 18 on the gear 15. A spr1ng 19 housed in the bevel gear 15 and surrounding the reduced end of the shaft 16 presses the gear 15 against the cone 17. T he pressure of these parts may be regulated by a nut 21 which may be adjusted along the threaded end of the shaft 16.v

It will be seen from the above that rota tion of the shaft 12 will rotate the gear 15 and will also frictionally rotate the Shaft 16. On shaft 16 is fixed a worm 22 which is in mesh at the outer periphery of the table 11 withy a Worm vvhee1`23. ,The worm 22 as shown is shaft 16 by key 24. The worm wheel 23 together with the table 11 will thus be frictionally rotated.

In alignment with the shaft 14a is a short shaft 30 on which is keyed a worm 31 as by means of the key 32 as shown. At one end of this shaft 30 is a clutch 'member 33 having teeth 34. On the shaft 15 is a similar clutch member 35 having clutch teeth 36. rlhe notches between adjacent teeth of these clutch membersl 33 and 35 are of greater width than the teeth so that theteeth of the clutch members have a large amount of lost motion between them, and the gear 14 must therefor move through a fairl large angle before the shaft 30 is rotate This clutch therefore gives the shaft 111a a limited free movement relative to the worm 31 and the table 11. 1t is essential that upon each reversal of the' power means 12, the free or idle movement between the members of the clutch 33 and 35 be sufficient to keyed dirgctly to the-` arrasa@ prevent movement of .the ,worm 31 until the worm 22 starts to drive the worm wheel 23 in either direction. i

From the above description it will' be seen that when the clutch teeth 311 and 36 of the clutch members are in contact, a positive drive is provided for the table 11 from the shaft 12. Also it will be seen that, as the gear 14 is larger than the gear 15, the angular rotation of gear 111 Will be le@ than that of 15. The effect of this is to give the frictionally driven worm 22 a more rapid rotating effecton the worm wheel 23 than on the worm 31. The gear 15, how# ever, frictionally engages the shaft 1" so that the worm 22 and shaft 16 may slipl relative to the gear 15.

The worm 31 is positively driven from gears 13 and 14 at a slower rate than worm 22 and the effect of this is to positively rotate the table 11 at a speed determined by the rotative speed and pitch of worm 31. Ris the worm 22 rotates morefrapidly than the worm 31, it forces the table 11 around as far as it will go thus taking up any play or lost motion between the parts of the positive driving` members and urging the table 11 always against oneside of the helix of the worm 31. i

If the rotation of shaft 12 is reversed in' order to rotate the table 1 in the opposite direction, it is necessary to provide means to first start the rotating movement by means of the frictionally driven worm, otherwise the 'effect would be to cramp the two worms toward opposite sides of the teeth on the worm wheel 23 and prevent any further rotation. To permit this frictionally driven worm 31 to start first, the clutch members 33 and 35 are formed as above described. c The first effect of the reversal of movement of shaft 12 is topstart the worm 22 1n\ the opposite direction and, by the time theidt motion of its driving members is taken i and it begins'to drive the table 11 in the opposite direction, the clutch teeth 34 and 36have taken up against their opposite surfaces after rotating through the angle determined by the differences in Width ofthe teeth and grooves formed in the clutch members 33 and 35. 1n other words, the positivo the worm 31 is rendered ineffective for an instant at each reversal of move-ment of the shaft 12 until the frictionally driven Worm 22 starts to rotate the element or table 11 in the opposite direction. AThis 33-35 then begins to drive the worm 31 and determines effectively the rotative speed of' the table 11.

rlhe worms 22 and 31 are shown disposed at right angles to'each other but it is obvious that they may be placed at any angle relative to each other that may be found de clutch sirable by varying the angle betvveen the bevel gears 14 and 15. As shown in Figure 1 the Worms are of the same form, that is,v

vorms may not be rotated by pressure applied to rotate the table.

eferring now to the modification shown in Fig. 2` it will he seen that two Worm Wheels are provided, and 51, both of these being fixed to and rotating;r with the shaft These are held in a suitable body portion such as a machine base, parts of which are shown at To the upper end of shaft 52, a table, such as that shown at 11, is rigidly secured. In mesh with the worm Wheels 50 and 51 are Worms 55 and 56 respectively mounted on shaft 57 and58. The driving means for these Worms and 56 and, therefore, for the shaft 52 comprise a short shaft 60, and a gear 61 which is 'in mesh with: geafr 62 and shaft 58. At the forward end of the shaft is a clutch member 63 meshing with correspondingv clutch member v64. Thel members of this clutch 63 and 64 are'I provided with a certain amount of lost motion by making the Width of the teeth of each part less than the Width of the grooves so that the shaft 60 may have a limited free movement relative to the Worm 55. Thiscluteh is similar in the clutch shown in Fig. 2 I and `further description is not, therefore, necessary.

The gear ,62 is provided with a conical portion 65 contacting' with a `conical porllt) vtive and a frictional drive 'tion66 on the shaft 58 and housed in the gz'ear 62 isa spring/adapted to force the gear .62`againsitithe con'ical portion 66. A nut 68 serves to adjust the' force of the sprin 67. 'Any driving means may be pro-- videdrto rotate the shaft 60 in either direc-l tion such as a gear 70.

It will be seen, therefore, that both a posihave been provided in this inodiiication for the shaft 52 .to Whicha table or other rotating element may be fastened. Rotationof the shaft 60 by means of gear 70 in either direction; will rotate lthe Worm Wheel 50 and consequently the shaft 52 will be positively rotated. The shaft 5S,v through gears 61 and 62 and the frictional clutch 65, 66 will be frictionally driven and thus will frietionally rotate the shaft 52. The Worm wheelso() and 51 may 'be provided with a slightly different number of teeth so that the worm wheel 51 tends te drive the shaft 52 at a slightly different speed-than the worm wheel SQ. The same result may be accomplished by providing a diierent number of teeth in gears 61 and 62 in Which case the worm wheels 50 and 51 would have the same number of teeth. In either case the Worm 56 is compelled to `slip every Way to.

between the parts ot' at the clutch 65-66, atfthe same time continuously forcing the-shaft 52 in one direction with sufficient force to take up-all lost motion between the positive driving means.

Reversing the direction of rotation of the shaft 60 serves rst to reverse the'worm 56 and thus start the rotation of the Worm 51 in the. opposite direction. As soon as the lost motion between the parts of the coupling 63-64 is taken up the direction of rotation of Worm Wheel 50 is reversed and' the shaft 52 is constrained to rotate in accordance with the speed of rotation of worm Wheel 50, the shaft 58 slipping within the gear 62 at the frictional clutch 65, 66.

In this embodiment of the invention the worms are of different form, that is, one

worm is a right hahd and the other worm.

left -hand helix. Also, different as shown but it pitch may be the same their pitch may be is obvious that the and the rotative speeds of the worms variedso that the effec.-

tive speed of the' frictionally ,driven worm is greater than that of the positively driven worm.

Thus, the shaft 52 may be rotated in either direction at a definite speed lot' revolution and the lost motion or back lash of its u driving members is always taken up and the table or other elementmounted on shaft 52 isheld positively against retrograde movement.

What I claim is:

l. Means for rotating an element compris ing' in combination, a positively driven Worm, a Worm Wheel in mesh therewith and rotatable with said rotatable element, a frictionally driven worm meshing with said worm Wheel, a clutch between the positively driven Worm and its driving means permitting;r a limited idle movement of said posi-- tive driving means relative to its worm, and common driving means for said worms` 2. A drag spindle gear comprising inconr bination, a rotatable element, reversible power means. t'rictional rotatingr means for said element, positive rotating means lfor said element, a clutch in said positive rotating means having inter-engaging members` permitting a limited idle angular movement the `positive rotating means so that the positive rotating means may remain inetfectiveuntil the frictional rotating means starts to drive the element upon each reversal of the power means, and

` common `driving means for said positive and loose connection therein permitting its driver, upon reversal of the power Ineens, to remain ineffective for an instant until the other driver becomes effective to rot-ete seid element in the opposite direction.

4. A oregspindle gear comprising in combination, an element to be rotated, reversible power means, and two drivers for rotating the said element connected, respectively, positively and 'frietionally to the power means, the seid positive connection serving to operate its driver et an eiiective speed slower than that of the other driver and e loose connectionY therein. permitting e limited idle r'otery movement between seid positive connection and its driver whereby, Upon reversal of the power means, the driver remains ineilective for an. instant until the other driver becomes effective to rotate said element in the opposite direction.

5. fr drag spindle geur comprising in combination, an element to loeroteted, reversible power means, and two drivers for rotating the said element connected, respectively, positively and frietionelly to the power means, the power connections for seid frietionally driven driver having lost motion therein, the said positive connection serving to operate its driver at an eiiceetive speed slower than that or the, other driver and e loose connection therein permitting o. limited idle rotary movement between seid positive Conner-tion and its driver whereby, upon reversal of the power ineens, tlie driver remains ineffective for en instant until the other driver overcomes the lost motion loe` tween its driving connections end becomes effective to rotate said element in the opposite direction.

G. A dreg'spindle gear comprising in combinetion. an element to be rotated, reversible power means, end two drivers for rotating the said element connected, respectively, positively and frictions-ily to the power means, the sztid positive connection being in alignment with its driverend serving to operate its driver et en effective speed slower than that or" the'otlier driver and a loose connection therein permitting e limited idle rotary movement between said positive connection and the driver whereby, upon nevose-e reversal ot the power means, the V meins, ineileetive during e sl movement or its driving` oon-nfA other driver becomes effective Y, element 'in the opposite -direetioi 7. drag spindle gear comp s binetion, en element to lie rot power Ineens, and two self-etopp for the seid element eonneoted, rer positively end trictionelly to means, the said positive connect' to operate its driver et an slower then thetrof other i loose connection therein po driver, upon reversal of the to remain ineieotiv tor .en ine, the other driver becomes seid element in the opposite di 8. A drag nindleg,

s binzttion, en elm-ent to ne power means, `end two seit-sr for the seid element, conneeteri, positively and frietionolly to means, the said positive connection to operate its driver et en eeetive slower than that of the other driver loose connection therein permitting e fini* idle rotary movement between seid connection and its driver, wherel versel of the power means, meins ineffective :tor an n ,te other driver becomes etieeti element in the opposite direc E). A drag spindle gear comp binetion, en element to be rotated power means, and two self-stoppn for the seid element, connected, i, i positively end rictionally to the means, the said positive oonneetion alignment with its driver s operate its driver at an eilen-tive than that of the otherdriver connection therein comprising clutch permitting its driver, upon of the power moans, to remain-ine for an instant until the other di.` eiteotive to rotate said element ii posite direction. i

ln testimony wliereo signature. 

